In many cases, data packets need to be sent between a mobile user equipment and a service entity. Transmissions can be performed both in downlink and uplink direction. For example, a server may send different packet flows for sound and video to the user equipment in a streaming session. The user equipment may send data to the service entity or may initiate a streaming session by control signaling. The service entity can also be another mobile user equipment. The transmission is performed over a mobile network and the service entity may be either part of the mobile network or it is able to exchange data packets with the network.
Customary mobile networks comprise a core network with core network nodes, e.g. a serving general packet radio service support node (SGSN) or a gateway general packet radio service support node (GGSN). The core network nodes allow the exchange of data with external networks such as the Internet or mobile or fixed networks of other operators. Furthermore, customary mobile networks comprise one or more access networks with access network nodes for controlling the radio transmission to the user equipment, commonly designated, e.g., as base station controllers, radio network controllers (RNC), Node B or base transceiver stations.
Depending on the type of packet traffic, the requirements for the transmission differ significantly. For example, voice transmission requires low delay and jitter while a limited amount of errors can be acceptable. Streaming sessions using packet buffers typically allow higher delays and jitter and the receiver can generally also correct or hide errors while file transfer can often be performed as best-effort traffic but normally requires error-free data. In addition, operators may choose to offer different qualities of service (QoS) depending on the user's subscription, i.e. they may choose to perform user differentiation. Accordingly, the provision of a defined quality of service is an important concept in the control of data traffic as described for example in technical specification 3GPP 23.107 V 6.3.0. of the 3rd Generation Partnership Project “Quality of Service (QoS) concept and architecture”.
The quality of service relating to a data transmission involving nodes of the mobile network and the user equipment is defined in different contexts. The user equipment and a core network node negotiate a PDP (Packet Data Protocol) context which specifies parameters for the transmission of data packets to and from the user equipment. In addition, further contexts are set up for different links between the service entity and the user equipment, e.g. a radio bearer between an access node and the user equipment, which specifies the transmission parameters on the radio link. The parameters of the further contexts are normally determined according to the PDP context. Packet flows between the service entity and the user equipment are then mapped to these contexts and forwarded accordingly.
The different contexts all involve attributes for specifying individual parameters of the traffic. In present mobile networks a plurality of such attributes is defined and they may either indicate binary or numerical values. Accordingly, a high number of possible combinations for the values of such attributes exist. In the negotiation or specification of the attributes for a context, also the user equipment can be involved. Depending on manufacturer, model and software, the user equipment can have different requirements and behavior in the specification procedure of the context, i.e. the setting of the attributes can also depend on the user equipment. This problem may partly be overcome by performing a specific configuration for the user equipment according to network operator, user equipment manufacturer and type. This is, however, inconvenient for the user and solves this problem only partly.
The differentiated services concept allows marking in the header of a data packet which quality of service should be used when handling the packet. A corresponding header field is for example defined in different versions of the Internet Protocol (IP). However, the marking of the data packets does not allow to forward quality of service information to all nodes controlling the quality of a data transmission in a mobile network because not all nodes are adapted to evaluate the headers. For example if the packet transmission involves packet fragmentation and/or encryption with later reassembly or decryption, the headers are normally not accessible to nodes handling encrypted packets or packet fragments.
Accordingly, it is a problem to specify the quality of service which the nodes in a mobile network use for the handling of data packets. In addition, it is also difficult for operators to specify how the resources controlled by the nodes in a mobile network are shared between different levels of the quality of service.